Heat lesion generators for producing clinical lesions or ablations in the human body have been commonplace for the last several decades. A particularly common type system is the radiofrequency lesion generator system exemplified by models produced by Radionics, Inc., of Burlington, Massachusetts These are power sources with a power source control and various or display readouts to monitor lesioning parameters, such as current, time, power, voltage, temperature, and impedance. The output of the lesion generator is connected to an electrode which is inserted into the body, and there is an indifferent connection to a reference electrode to complete the electrical circuit An operator would raise the power control to increase the temperature of the tip, which may be monitored, to produce the desired lesion at a given target temperature for a given time.
What has not been done heretofore is to provide real-time graphic means on a graphic display module which shows the course of the lesion as the heating proceeds. This implementation would be very helpful and useful in the neurological and cardiac fields, especially in the cardiac field where a catheter is inserted through vessels into the heart muscles area Here there are strong dynamic effects caused by the pulsation of the heart, passage of fluid, and impingement on tissue, all of which affect the impedance and can affect the course of the temperature rise during heating To be able to watch the impedance and the temperature on a graphics display would be extremely illuminating and could tell the operator at what point the lesion is satisfactorily large and when to shut off the unit or to cut back the power, Also having capabilities to watch the ECG or other electric output or potentials from the lesion tip through the lesion generator while you are making the heat lesion would give added and very important insight into the effect of the heat lesion on the target tissue
Thus, an objective of the present invention is to provide in a lesion generator system an appropriate graphics display to display in real time, in color the various essential parameters for heat lesioning. In addition, an objective of the invention is to provide benchmark or set point values on the graphic display so the operator has an instant impression of the desired end point of the heating process and where the temperature, impedance, and other parameters are relative to various desired set values Yet another objective of this invention is to provide connections to monitor and display the physiologic electrical signals from the lesion electrode tip to see their change during the lesion.